LOCATION LOCODA OREstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, acid, mesic Typic Fluvaquents
TYPICAL PEDON: Locoda silt loam, cultivated. (Colors are for moist soil unless otherwise noted.)
Ap1--0 to 4 inches; dark grayish brown (10YR 4/2) silt loam, few fine distinct dark yellowish brown (10YR 4/6) mottles; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and many very fine roots; common fine and very fine irregular pores; many medium vertical pores; very strongly acid; clear smooth boundary. (4 to 10 inches thick)
Ap2--4 to 10 inches; gray (5Y 5/1) silt loam, common fine prominent dark yellowish brown (10YR 4/6) mottles; weak fine subangular blocky structure; slightly hard, friable, sticky and slightly plastic; common very fine roots; common very fine irregular pores and many vertical pores; very strongly acid; gradual smooth boundary. (0 to 6 inches thick)
Cg1--10 to 22 inches; gray (5Y 5/1) silty clay loam, common fine and medium prominent strong brown (7.5YR 4/6) mottles; massive; hard, firm, sticky and plastic; common very fine roots; few fine and very fine irregular pores; very strongly acid; gradual smooth boundary. (0 to 14 inches thick)
Cg2--22 to 26 inches; gray (5Y 5/1) silty clay loam, common fine and medium prominent dark yellowish brown (10YR 3/6) mottles; massive; hard, firm, sticky and plastic; few very fine roots; few very fine irregular pores; common lenses of very dark brown (10YR 2/2) organic material; very strongly acid; gradual smooth boundary. (0 to 15 inches thick)
Cg3--26 to 60 inches; gray (5Y 5/1) silt loam, few fine prominent strong brown (7.5YR 4/6) mottles; massive; hard, firm, sticky and plastic; very few very fine roots; few very fine irregular pores; very strongly acid.
TYPE LOCATION: Columbia County, Oregon; Beaver drainage district about five miles north of Clatskanie; 50 feet south of the Dike Road; 1/4 mile WSW of gate to PGE Beaver Power Plant; NW1/4 NW1/4 section, 21, T. 8 N., R. 4 W.
RANGE IN CHARACTERISTICS: The soil is saturated with water throughout the year and is subject to freshwater overflow during spring floods and high tides unless diked and artificially drained. The mean annual soil temperature ranges from 53 to 55 degrees F. The particle-size control section has an irregular decrease in organic matter with depth; it is 18 to 35 percent clay with less than 15 percent coarser than very fine sand.
The A horizon has hue of 10YR or 2.5Y, value of 3 or 4 moist, and chroma of 1 through 3. It has common distinct or prominent mottles to the surface. It is 6 to 10 inches thick.
The C horizon has hue of 2.5Y to 5B, value of 4 or 5 moist, and chroma of 0 to 1. The lower part in some pedons has hue of 5B and 5Y that changes on exposure to air to neutral 5Y or 2.5Y hue. This horizon is stratified silt loam and silty clay loam, and commonly has 2 to 5 mm thick lenses of decomposed organic materials.
COMPETING SERIES: These are the Bonnie and Piopolis series. Bonnie and Piopolis soils have iron-manganese concretions throughout the particle-size control section and have soil structure below 10 inches.
GEOGRAPHIC SETTING: Locoda soils are in nearly level or concave positions on flood plains. Slopes are 0 to 3 percent. Elevations range from 0 to 20 feet. The soils formed in recent silty alluvium. They are in a climate with warm moist summers and cool wet winters. The mean annual precipitation is 50 to 80 inches. Mean July temperature is 62 to 68 degrees F., mean January temperature is 36 to 40 degrees F., and mean annual temperature is 50 to 54 degrees F. The frost-free period is 165 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Crims and Wauna soils. Crims soils are organic soils. Wauna soils have a cambic horizon and chroma of 2 in some subhorizons. Crims occupies the same concave position as Locoda, while soils occupy adjacent convex or gently sloping positions.
DRAINAGE AND PERMEABILITY: Very poorly drained; ponded; moderately slow permeability.
USE AND VEGETATION: When diked and drained, the soils are used for pasture and truck crops. Areas outside the dike are used for wildlife habitat and pasture. The native vegetation is cottonwood, willow, ash, grasses, forbs and tussocks (Juncus sp.)
DISTRIBUTION AND EXTENT: Northwestern Oregon along the Columbia River. The soil is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Columbia County, Oregon, 1983.